Head gasket or what!?!?

[insomniA4]

So I was almost 100% positive that I had a blown head gasket. Now that I have driven the car some more I am not so sure....I need some help diagnosing the problem if possible....my car is an 04 b6 1.8t Quattro 6spd (mods in my sig)...after sitting for about a month I drove it and noticed while sitting at a dead stop there would be tons of sweet smelling white smoke dumping out the exhaust....on top of this my car would misfire when under hard acceleration and I would get a blinking check engine light...my coolant is def leaking somewhere because the level keeps dropping constantly after driving...well this seems like a straight up head gasket problem to me no questions asked...however I've noticed that when I drive my car and keep it under 5 lbs of boost or so it won't smoke at all even when parked...the car won't misfire and drives fine to be honest...the car has no idle issues either...could this still be the head gasket? I was certain it was but when babying the car it seems to drive normal....however if I hit 5-10 lbs of boost or more it will start dumping smoke again (only when I come to a stop) and will misfire...any input would be much Appreciated...

[insomniA4]

Anyone have any experience with something like this?

[old guy]

The fact that your exhaust blows sweet smelling white smoke is a pretty good indication that coolant is getting into the exhaust. The two most common sources of coolant in the exhaust would be the head gasket or a cracked cooling jacket in the turbo. Based upon your observation that the smoke seems to be tied to the amount of boost I would suspect the turbo is your problem.

[insomniA4]

I was under the impression there was no coolant running through our turbos?! Just oil...Please correct me if I am wrong...I agree that it does feel boost related and the fact that it does not constantly spew smoke makes me think it's not the head gasket...I don't know what to think anymore

[chad99]

We indeed have both coolant and oil feeds and returns at the turbo, your problem really sounds more like the turbo is leaking coolant.
When my headgasket was bad the car always had cold start misfires

[hightime80]

I was under the impression there was no coolant running through our turbos?! Just oil...Please correct me if I am wrong...I agree that it does feel boost related and the fact that it does not constantly spew smoke makes me think it's not the head gasket...I don't know what to think anymore

You are wrong. All you got to do is look at top of the turbo and you can see two lines going into it. One is oil supply and the other is the coolant supply. Listen to OG. Your turbo has shit the bed. Be glad it aint your HG.

[insomniA4]

Thanks for the reply guys...I was hoping it was the turbo...I was just thrown off because it seemed like it was building boost ok...until it would misfire that is but it would make sense seeing that if I drive my car and try to keep it in vacuum or under 5 lbs at least it drives normal. ..except for the fan constantly running but I'm assuming that's the coolant Temp sensor? Perhaps it's all connected somehow?

[stew44]

Are all the spark plugs fouled equally or just one?

[hightime80]

Thanks for the reply guys...I was hoping it was the turbo...I was just thrown off because it seemed like it was building boost ok...until it would misfire that is but it would make sense seeing that if I drive my car and try to keep it in vacuum or under 5 lbs at least it drives normal. ..except for the fan constantly running but I'm assuming that's the coolant Temp sensor? Perhaps it's all connected somehow?

It could a failed FCM, water in ecu box or maybe the CTS, I would scan for codes before you throw parts at it.